Ampex 351 - Page 82

Record Azimuth Adjustment
Step 1:
Set the oscillator at 500 cps.
Step 2:
Step 1:
Step 3:
Step 2;
Step 4:
Step 3:
Step 5:
Step 4:
Step 6:
Head azimuth adjustment
8-9
calibrating the record level (see Re 
produce Level Control Calibration).
Set the RECORD LEVEL knob to a
position that will obtain a zero reading
on the VU meter.
Using a long shank screwdriver (to
avoid burns from the hot electron
tubes), adjust the record level poten 
tiometer for a zero VU reading.
NOTE
If it is desired to make this azimuth
adjustment using the VU meter in 
stead of the VTVM, place the PLAY 
BACK LEVEL control in the full
clockwise position and adjust the azi 
muth nut to obtain a maximum VU
meter reading.
Set the audio oscillator to 7500 cps for
3% ips, 15 kc for 7*Z j and 15 ips.
89-0144
Issue A
Place the METER AND OUTPUT
SWITCH in the RECORD LEVEL
position.
Set the audio oscillator to 500 cps.
Leave the METER AND OUTPUT
SWITCH in the PLAYBACK position.
Set the RECORD LEVEL knob to
obtain a VU meter reading of approx 
imately — 20 ( — 12 on VTVM).
Place METER and OUTPUT SWITCH
in the RECORD LEVEL positron.
With the nut driver, rotate the adjust 
ment nut on the left side of the record
head (as the user faces the front of
the equipment) to obtain a maximum
VTVM reading.. Several peaks may
appear, but the maximum peak is
obvious because- it is much greater
than the minor peaks.
Place the METER and OUTPUT
SWITCH in the PLAYBACK position.
Overall Frequency Response
To avoid tape compression, frequency re 
sponse at 15 ips tape speed should be made
at least 10 db below operating level ( — 2 dbm),
at 3% and 7*/2 ips at least 20 db below oper 
ating level ( — 12 dbm). The standard align 
ment tapes are recorded at a higher level to
facilitate measurements on the VU meter.
Step 1: Place the METER and OUTPUT
SWITCH in the RECORD LEVEL
position.
CAUTION
The right hand nuts are factory set.
DO NOT ADJUST THEM.
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